Working Principle It is rotating 360 degree through a shaft with spiral bands, it can lift Punch, rising and declining vertically at different angles, dotting with the impact of elastic spring, the handle shaking one circle will make a straight line on the specimen, the space of 10 mm, a total of 30 points = 300 mm long. Main technical specifications 1. The longest distance of 400 mm 2. The form of 490 millimeters long, 200 millimeters wide, 300 millimeters high 3. Each net weight 22kg